Slack adjuster



Jan. l, 1957 J. H. VAN Moss, JR

SLACK ADJUSTER Filed Dec. 29, 1953 .nays

NOE

INVENTOR. JOHN H. VAN MOSS, JR.

BY/M// M/ ATTORNEYS United States Patent O SLACK ADJU STER John H. Van Moss, Jr., Chicago, Ill. Application December 29, 1953, Serial No. 400,984 7 Claims. (Cl. 18S- 198) This invention relates to railway braking apparatus, and particularly to slack adjusters for use in such apparatus.

In the operation and use of railway braking equipment, it is desirable that the working stroke of the brake cylinder be maintained within predetermined minimum and maximum limits so as to insure proper operation of the braking system while at the same time minimizing the amount of compressed air that is required in each brake application. In the past, it has been found that the gradual increase in the amount of movement that must be applied to the several brake hangers of a railway car, due primarily to progressive wear of the brake shoes, increases the required piston travel beyond the amount that is considered to be desirable or permissible, and many elorts have been made to remedy this condition so as to maintain the piston travel within the desired range, while at the same time insuring proper operation of the brakes for all conditions of wear. The apparatus utilized for remedying this undesirable condition has, in most instances, been termed slack adjusting means, in that, such apparatus was intended to remove or reduce the slack in the brake rigging used to transmit the forces from the brake cylinder to the brake beams at the several sets of wheels. Such slack adjusters have taken many different forms, and have been applied to the brake rigging of both passenger and freight cars. The prior slack adjusters of which I am aware have been relatively ditlicult to intsall land maintain, and in view of this, it is the primary object of the present invention to enable the slack in railway brake rigging to be taken up by means that are simple and inexpensive in character, rugged in operation, and relatively easy to install on the various types of brake rigging that are now employed in railway equipment. More specifically, it is an object of the present invention to enable slack adjusting means of a simple character to be readily and easily associated with a pull rod of a brake rigging in such a way that the elective length of the pull rod is progressively reduced as the brake applying movements are imparted thereto, thus to enable a greater range of brake shoe movement to be attained for a given amount of piston travel in the brake cylinder.

Other and further objects of the present invention will be apparent from the 'following description and claims and are illustrated in the accompanying drawing which, by way of illustration, show preferred embodiments of the present invention and the principles thereof and what I now consider to be the best mode in which I have contemplated applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art wihout departing from the present invention and the purview of the appended claims.

In the drawings:

Fig. 1 is a schematic plan view illustrating a freight car brake rigging embodyingthe features of the invention;

2,776,028 Patented Jan. 1, 1957 Fig. 2 is a fragmentary side elevational view of the apparatus of Fig. l;

Fig. 3 is a perspective view showing one form of slack adjusting or compensating means embodying the features of the invention;

Fig. 4 is a fragmentary plan View of a modiiied embodiment of the invention whereby compensating means are employed in a dilerent relation, the parts being shown in their released relationship;

Fig. 5 is a fragmentary portion of Fig. 4 showing the parts in an actuated or brake applying relationship; and Fig. 6 shows a further modification of the invention.

For purposes of disclosure, the invention is herein illustrated in Figs. l and 2 as applied to an AB brake rigging which constitutes one form of brake rigging that is utilized on railway freight cars, and as shown in Figs. 1 and 2, the frame 10 of a freight car is illustrated diagrammatically as having a conventional brake cylinder 11 mounted thereon, this cylinder 11 having the usual piston rod 12 and push rod 13, such push rod being pivotally connected at 13P to a cylinder lever 14. This cylinder lever has its opposite end connected by a pivot 141n to a pull rod 15 that extends to the right in Fig. 1 and has the usual connecting clevis 18 associated with its right hand end for connection in the usual way to the respective brake beams of the adjacent truck.

The cylinder lever 14 is connected by a sectional center pull rod 20 to a brake lever 21, the brake lever 21 being pivoted at one end on a fixed pivot 21P and being pivoted at its other end to one end of a pull rod 22. This pull rod 22 extends to the left and at its other end has a conventional clevis 25 for connection in the usual manner to the brake beams of the adjacent truck.

The present invention is illustrated in Fig. l as being associated with the sectional center pull rod 20, and means are associated with the sectional rod 20 for electually reducing the overall elective length of the sectional rod 20 as endwise movement is applied to the rod 20 by operation of the brake cylinder 11. In the present instance, the sectional rod 20 shown in Fig. 1 comprises two sections 20-1 and 20-2. The section 20-2 is pivotally connected at one end to a pivot on the cylinder lever 14, and is connected at its other end by an intermediate pivot 27 to one end of the sectional 20-1. The other end of the section 20-1 is pivotally connected to the brake lever 21.

The slack adjusting or compensating means of the present invention are associated with the intermediate pivot of the pull rod 20 such as the pivot 27, and such means are eective, as will hereinafter be described, to impart progressive lateral shifting movements to the intermediate pivot 27 as an incident to brake applying endwise shifting movements of the sectional pull rod 20. Thus, a compensator 30 is associated with .the intermediate pivot 27, and this compensator may be of the form that is illustrated in Fig. 3 of the drawings. Thus the compensator 30, in the form herein shown, comprises a mounting bracket 32 having a horizontal flange 33 that is adapted to be bolted to an under surface of the car frame 10, and it has a depending vertical flange 34 upon which a mounting lug 35 is secured so as to project in a horizontal direction from the vertical flange 34. This lug 35 serves to support a vertical pivot 36 upon which one end of a compensating link 37 is pivoted, the other end of the compensating link 37 being pivoted on the intermediate pivot such as the pivot 27. In the present instance, and in order to obtain a balanced force-transmitting action between the pull rod 20 and the link 37, this link 37 is made in two spaced parts, 37U and 37L, that are mounted respectively against the upper and lower surfaces of the mounting lug 35 and against opposite sides of the sectional pull rod at the intermediate pivot.

The relationship of the pivot36 with respectto the direction of brake applying movement of the pull rod 20 is important in attaining thedesired compensating action under the present invention, andas shown in Fig. l, the pivot 36 is normally located so as to be spaced along the pull rod 2t) between the intermediate pivot 27 to which it is attached and the end of the pull rod to which the pulling movement is imparted. This results in pivotal or rocking movement of the compensating lever 37 about its pivot 36 so as to approach a perpendicular relationship with respect to the direction of pulling movement as such pulling movement progresses. This serves to force the intermediate pivot laterally so that the pull rod 20 has the ysections 2Q-1 and 20-2 thereof disposed in a somewhat zig-zag relationship, and this serves to reduce the effective length of the pull rod. Hence, the operation of the brake cylinder through the usual or specified maximum range is effective to impart greater movement to the brake shoes than would otherwise be possible.

The invention has been illustrated in Figs. l and 2 of the drawings as having a single compensating unit 3i), and with this unit located in or in operative association with the center rod of the brake rigging, but it will be evident that in some instances the desired compensation may be obtained through the use of more than one compensating unit, as shown in Figs. 4 and 5, or in Fig. 6, of the drawings.

Thus in theembodiment of the invention shown in Figs. 4 and 5 of the drawings, a generally similar brake rigging is employed, but the usual one-piece center rod 12th is employed, and the pull rods that extend respectively from the levers 14 and 21 are embodied as sectional pull rods 115 and 122 respectively. Each of the sectional pull rods 115 and 122 is arranged under the present invention to be shortened as an incident to the application of pulling movement thereto, and this is accomplished through the association of compensator unit 130 with each of these pull rods 115 and 122. The compensating units 130 are of the same construction as the compensating unit 30 hereinbefore described, and by reason or the fact that the pulling movements are applied in opposite directions to the pull rods 115 and 122, these units are disposed in an opposite relationship with-respect to each other.

rl`hus, the compensating unit 130 that is associated with the pull rod 115 has the fixed ypivot 36 thereof disposed to the left of the intermediate pivot 127 of the rod 115. With respect to the pull rod 122, the pivot 36 of the compensator unit is disposed to the right with respect to the intermediate pivot 127, and hence when the brake applying movements are applied to the pull rods 115 and 122, these rods are effectually shortened, as will be evident by a comparison of Fig. 4 with Fig. 5 of the drawings. ln Fig. it will be noted that the sectional pull rod 115 is shown with the intermediate pivot 127 shifted laterally with respect to its normal position, and hence the eifective length of the pull rod 115 between its end pivots is substantially reduced.

In the form illustrated in Fig. 6 of the drawings, a pull rod 21S-22d is illustrated which may constitute any pull rod of a brake rigging such, for example, as the center rod of Fig. l, or the pull rods 15 or 22 of Fig. l, and in Fig. 6 the pull rod 21S- 220 has been illustrated as being made up of three sections that are connected in series with each other by intermediate pivots 227. Each of the intermediate pivots 227 has a compensator unit 230 associated therewith, and these compensator units may be of the form illustrated in Fig. 3 and described hereinbefore. The compensator units 230 are in each instance disposed so that the fixed pivot 36 thereof is spaced along the pull rod from the associated intermediate pivot 227 in the general direction of that end of the pull rod to which the pulling movement is applied. In Fig. 6, the direction of pull is indicated by arrow and an appropriate legend. Moreover, the compensator units 230 are disposed on opposite sides of the pull rod 21S-220, thus A to cause ,the associated intermediate pivots to belaterally displaced in opposite directions when pulling movement is applied to the pull rod. This effectually shortens the pull rod 21S-22d, as has been indicated diagrammatically in dotted lines in Fig. 6.

From the foregoing description it will be apparent that the present invention enables the slack in railway brake rigging to be taken up by means that are rugged in their operation, simple and inexpensive in their structure, and relatively easy to install in various types of brake rigging. Furthermore, it will be evident that the slack adjusting mechanism of the present invention is operable to effectually reduce the length of a pull rod in a brake rigging, thus to enable a greater range of brake shoe movement to be attained for a given amount of piston travel.

Thus while l have illustrated and described the preferred embodiments of my invention, it is to be understood that these are capable of variation and modication, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

l. In ia brake -rigging for railway equipment, la multiple-section pull rod including Ian actuating end to which endwise pulling forces are to be applied to pull said rod in a predetermined endwise direction, an actuated end for Itransmitting ibrake applying movement lto other portions of .the brake rigging, tand an intermediate pivot connecting adjacent sections of the rod for pivotal movement about la :common axis, and a slack adjuster comprising a lcompensating lever having one end pivoted on `a iixed pivot located between said actuating end and said intermediate pivot and having its other end pivoted tto said intermediate pivot to displace said intermedi-ate pivot laterally with respect to sa-id direction and thus eifectually shorten said pull rod yas endwise movement is imparted to said pull rod in said predetermined direction.

2. `In a brake rigging Ifor railway equipment, a rsectional pull rod including lan actuating end to which endwise pulling forces are .to tbe applied to pull said rod in a predetermined endwise direction, an actuated end for transmitting brake lapplying movement to other portions of the brake rigging, and an intermediate pivot connectting `adjacent sections `of the rod for pivotal movement Iabout a common axis, and means permanently mounted in la predetermined position and operatively connected to said intermediate pivot 'to displace said intermediate pivot laterally with respect to said direction as Asuch endwise movement is imparted .to said pull rod so as to effectually shorten said pull frod.

3. 11n a brake rigging for railway equipment, fa sectional pull rod including an actuating end to which endwise pulling forces are to be applied to pull said rod in an endwise direction, an actuated end for transmitting brake Iapplying movement to other portions of the lbnake rigging, iand an intermediate pivot connecting ladjacent sections of |the rod for pivotal movement about a common taxis, `a bracket mounted in a iixed position `adjacent to said intermediate pivot, rand means connected between said intermediate pivot and said ibnacket .and operable to displace said intermediate pivot laterally with respect to said direction and thus effectually shorten said pull Irod as such endwise movement is imparted to said pull rod.

l4. In a :bnake rigging for railway equipment, la multiple-section pull @rod including an actuating end t-o which endwise pulling forces are Ito be applied to pull said rod in a predetermined endwise direction, an actuated end for .transmitting lbrake applying movement to other portions of the brake rigging, and at least two intermediate pivots connecting ladjacent sections of 'the rod 'for pivotal movement about a common axis, and at least two yslack adjusters individually associated with the respective intermediate pivots iand each comprising la compensating lever having one end pivoted on a txed pivot located between said actuating end and the related intermediate pivot and having its other end pivoted to said related intermediate pivot to displace said intermediate pivot laterally with respect to ysaid direction, :said slack adjnsters being disposed on opposite sides of said sectional pull rod so as to displace the related intermediate pivots in opposite directions and thus effectual-ly shorten said pull rod as endwise movement is imparted to said pull rod in said predetermined direction.

5. In -a brake rigging for railway equipment, Ia pair of sectional pull rods each including :an actuating end to which endwise pulling yforces are to 'be applied to pull said rods in opposite endwise direction, and each inaving lan actuated end tor transmitting 'brake applying movement :to other portions ofthe Ibrake rigging, 4and each also having an intermediate pivot connecting its adjacent sections for pivotal movement about a common axis, land means permanently mounted is la predetermined position :and operatively connected Ito each of said intermediate pivots to displace said intermediate pivots laterally with respect to said endWi-se directions as `such endwise movements are imparted to lthe respective pull rods so las to effectual-ly shorten each of said puil rods.

y6. 'In 1a lbnake rigging Ifor railway equipment, a pair of sectional pull rods each including an intermediate pivot connecting its adjacent sections for pivotal movement about la common axis, a fbnacket mounted in :a xed position adjacent to each of said intermediate pivots, and

means connected between the respective intermediate piva ots and the respective ybrackets and operable to displace said intermediate pivots laterally with respect to the 1'e spective directions of movement of said rods `and thus effectually shorten :said pull nods as endwise movements .are imparted to said pu-l-l rods..

7. lIn a brake rigging :for :railway equipment, fa pair of sectional pull rods each including an intermediate pivot connecting its :adjacent sections for pivotal movement about la common laxis, means for imparting endwise ibrake applying movements to said rods in opposite directions, and a slack ladjuster mounted in iixed relation adjacent to the respective intermediate pivots and lhaving compensating levers extend-ed .therefrom to said intermediate pivots to displace :said intermedi-ate pivots laterally with respect to the respective directions of movement of said rods and thus effectnaliy shorten said pull rods es endwise movements are imparted to said pull rods.

References Cited in the le of this patent UNITED STATES PATENTS 1,7|'l7,697.i Lankheet June 118, l1929 1,928,083 Warren Sept. 26, 1933 2,041,268 Sewell May 19, 1936 2,165,985 Schwentier July 11|1, 1939 FOREIGN PATENTS 319,197 Germany Feb. 27, `1920 

